Open-Circuit Flag Bits (Oc0 To Oc7); Over-Range Flag Bits (O0 To O7); Under Range Flag Bits (U0 To U7) - Spectrum Controls 1769 Series User Manual

3-12 Chapter 3: Module, Data, Status, and Channel Configuration
NOTE
User's Manual Pub. 0300244-02 Rev. A
module. This "invalid data" condition can occur (bit set) when the download of a
new configuration to a channel is accepted by the module (proper configuration)
but before the A/D converter can provide valid (properly configured) data to the
1769 bus master/controller. The following information highlights the bit
operation of the Data Not Valid condition.
1. The default and module power-up bit condition is reset (0).
2. The bit condition is set (1) when a new configuration is received and
determined valid by the module. The set (1) bit condition remains until
the module begins converting analog data for the previously accepted
new configuration. When conversion begins, the bit condition is reset
(0). The amount of time it takes for the module to begin the conversion
process depends on the number of channels being configured and the
amount of configuration data downloaded by the controller.
If the new configuration is invalid, the bit function remains reset (0) and
the module posts a configuration error. See Configuration Errors.
3. If A/D hardware errors prevent the conversion process from taking place,
the bit condition is set (1).

3.4.3 Open-Circuit Flag Bits (OC0 to OC7)

Bits OC0 through OC5 of word 6 contain open-circuit error information for
channels 0 through 5, respectively. Errors for the CJC sensors are indicated in
OC6 and OC7. The bit is set (1) when an open-circuit condition exists. See
Open-Circuit Detection on page 4-3 for more information on open-circuit
operation.

3.4.4 Over-Range Flag Bits (O0 to O7)

Over-range bits for channels 0 through 5 and the CJC sensors are contained in
word 7, even-numbered bits. They apply to all input types. When set (1), the
over-range flag bit indicates an input signal that is at the maximum of its normal
operating range for the represented channel or sensor. The module automatically
resets (0) the bit when the data value falls below the maximum for that range.

3.4.5 Under Range Flag Bits (U0 to U7)

Under-range bits for channels 0 through 5 and the CJC sensors are contained in
word 7, odd-numbered bits. They apply to all input types. When set (1), the
under-range flag bit indicates an input signal that is at the minimum of its normal
operating range for the represented channel or sensor. The module automatically
resets (0) the bit when the under-range condition is cleared, and the data value is
within the normal operating range.